When loosening a tightly secured nut or bolt, a large torque is necessary to apply to the nut or bolt and this is generally achieved by using a tool such as a wrench. The nut or bolt to be loosened could get rust so that it is difficult to be loosened, the user often uses another tool to strike the body of the wrench so as to produce a sudden and large torque to shake and loosen the nut or bolt. This action can only proceeded when there has an space large enough to allow the swing of the tool. Generally, the wrench itself cannot provide the necessary sudden and large torque.
The present invention intends to provide a torque wrench wherein the head portion of the wrench is engaged with a means in the body of the wrench so that when rotating the wrench, the head portion is first rotated about a pivot to provide a large and sudden torque to loosen the nut or bolt. The torque wrench of the present invention effectively mitigates and obviates the disadvantages mentioned above.